The professional team on the Absa Towers West project includes five Green Star accredited professionals, and the project will soon be registered with the Green Building Council of South Africa (GBCSA) for a Green Star Office version 1 rating.

“The submission process follows three months after practical completion in March 2011. The project is aiming at a four star rating,” says WSP Green by Design sustainable building consultant, Marloes Reinink.

A green building is one which reduces environmental impact in terms of energy consumption, water consumption, material sources, and emissions. It provides improved indoor environmental quality, which has been proven to improve the productivity of employees in the building.

- In terms of location, the building is in the central business district, therefore close to many amenities and public transport for staff working in the office. It also contributes to urban regeneration and making the city a safer place.
- With regard to water, the project has a grey water system which will be the largest system installed in South Africa. The system has a capacity of recycling 43 000 litres (43 m3) of water a day. The water is collected from the showers in the gym and is re-used to flush the toilets and urinals.
- For lighting, a digital addressable lighting interface system will be installed in the building, and combined with very efficient light fittings. All light fittings are fitted with motion sensors and daylight dimmers. Motion sensors are also installed in the parkade to keep the energy for lighting to a minimum.
- The project also has a very well designed façade. The building has double glazing with thermal breaks, and sufficient thermal insulation in the walls.
- The heating ventilation and cooling system has incorporated an economy cycle, which uses outside air to provide free cooling when outside conditions are favorable. This reduces the energy consumption associated with mechanical cooling of the air. The system also allows for night-time flushing of the building to cool down the building structure at night.
- Initiatives involving construction materials are polyvinyl chloride minimisation, promoting the use of sustainable timber, promoting the use of local products, the use of low volatile organic compound paints and carpets to improve the indoor air quality, and the contractor is ISO 14001 accredited.
- The gas-powered energy centre, located at the campus, is provided to serve the office’s needs. The energy centre will supply the majority of the campus electricity consumption on weekdays. This provides additional security of supply to the campus in addition to relieving load on the City Power electricity grid during peak times.

Gas-powered generation is a cleaner form of generation with about half of the emissions of the coal-fired generation which it displaces. This is expected to save about 17 136 tons of carbon dioxide equivalent a year, and Absa is in the process of applying for carbon credits for this initiative.

When Towers West is completed, an additional 3 580 permanent Absa staff members will be working in the CBD, which will result in about R1,2m a month in additional revenue for the city.